Mri: too close for comfort

Up to one third of patients being tested with magnetic resonance imaging (MRI) scanners have felt so claustrophobic that the tests have had to be abandoned.

A study of nearly 6000 MRI examinations over two years at the MRI Institute at the University of Vienna found that 50 of the tests had to be aborted because of patients' reaction to being placed in the tunnel.

The test, used to investigate diseases of the brain and spinal cord or other organs or soft tissues of the body, entails having the patient climb inside a massive cylindrical magnet weighing up to 500 tons large enough to envelope the patient's entire body. While you are inside the magnet, a quick pulse is applied, causing a disturbance in the nuclei of the hydrogen atoms of the body. When this stops, the nuclei emit an electrical "echo" which is picked up by the machine and converted into an x-ray like image.

The Viennese study found a better outcome with a newer, wider and shorter tunnel.